Incorrect packet validation in FreeBSD's packet filter (pf) allows unbounded recursion when parsing SCTP chunk parameters. Crafting a malicious SCTP packet can trigger a stack overflow, causing the kernel to panic. The failure is a denial‑of‑service condition that affects system stability without directly leaking data or code execution. The weakness corresponds to uncontrolled recursion (CWE‑674) and out‑of‑bounds write (CWE‑791).

This flaw concerns any FreeBSD machine where pf is enabled and processes traffic, regardless of the firewall ruleset. No specific version range is supplied in the advisory, so all deployments that use the affected pf code are potentially vulnerable until the security release is applied.

The vulnerability can be triggered remotely by an attacker who can send SCTP packets to the target. Although the exploit does not provide direct code execution, the induced kernel panic effectively brings the node down, which may allow a persistent denial‑of‑service attack. The EPSS score is < 1% and the flaw is not listed in the CISA KEV catalog, while the CVSS score of 7.5 indicates a medium‑to‑high severity. Combined with the lack of mitigating controls, this suggests a significant risk when the affected system is exposed to untrusted SCTP traffic.